Customized OEM Liquid Flow Sensor Solutions

Customized OEM Liquid Flow Sensor Solutions
Sensirion manufactures CMOSens microsensors in high volumes. Liquid flow sensing solutions for flow rates below 80 ml/min down to the microfluidic sector and sub nano litre resolutions are Sensirion’s unique strength. For volume applications we help to develop a superior product and manufacture your tailored, calibrated, digital liquid flow sensor solution. The non-invasive liquid flow sensor technology using MEMS thermal principles has been patented by Sensirion.

Sensirion is ready to modify existing standard designs or to develop totally new solutions for your product as long as a certain quantity is needed.
Planar packaging technology - example of integration
The unique CMOSens planar packaging technology is applicable for annual quantities starting a 10’000 pieces per year. This innovative design enables Sensirion's highly sensitive thermal flow sensor microchips to measure non-invasively through the wall of a flow channel inside a planar microfluidic substrate (US Pat. 6813944). The design provides unique sensitivity for liquid flow measurement and bubble detection even in the microliter range. A small digital CMOSens microchip (2.2 x 3.5 mm) is bonded to the microfluidic channel substrate. Beside the sensor element it houses the complete digital intelligence as well as the memory necessary for signal linearization, temperature compensation and self-test algorithms. The chip provides a fully digital I2C interface and can operate over a supply voltage of 2.8 to 3.3 V. Fluidic ports on the bottom facilitate easy integration of discrete sensors for manifold designs if necessary. The sensor boasts a short flow sensing response time of around 40 ms, and sensor resolutions down to 0.5 nl/min are feasible.

Features
Flow rates from nl/min up to 100 ml/min
Totally non-invasive sensing principle
High speed: 40 ms response time
Supply voltage 2.8V - 3.3V
Digital IC interface

For custom specific designs in general our core competences include:
Design and mass production of MEMS flow sensors
Packaging & calibration in high volumes
Bio compatibility and high chemical resistance
Short response times (ms-range)
Small size micro and nano flow sensors
Non-invasive / media isolated (one wetted material only)
High pressure resistance
Ultra high sensitivity (< 0.5 nano liter/min)
Feasible Specifications
Fludic: Examples

Liquids: H2O, Methanol, Blood, EtOH, ACN...
Dead volume free (straight capillary only)
Absolute pressure: 0 ... 1000 bar
Response time: ms-range
Resolution: down to 0.1 nano liter/min.
Liquid flow range: +/- nl ... 100 ml/min. (bi-directional)
Temperature range: -40 ...120 °C

Electrical
Interface: I2C, RS-232, RS-485, analog
Power supply: 2.6V ... 24V
Fail safety: self test functionality, auto compensation
Power consumption: < 100 micro Joule per measurement feasible!

Packaging
Wetted materials upon your choice glass, ceramics, PEEK, stainless steel, …
Optionally protection category IP54, IP65, IP67
Disposable components based on highly integrated sensor chips